Vehicles conventionally regarded as having a lateral travel system include large-scale transporters, some loaders, and the like, and in fork lift devices, these include reach-type electric vehicles. Furthermore, there are also side fork lifts for handling long materials, which have a mast or forks installed in a lateral direction with respect to the movement of the vehicle. However, there is no counter-type fork lift which is able to provide functions similar to side forks, in addition to standard tasks, by performing lateral movement. In order to achieve a fork lift of this kind, it is necessary to steer the front wheels, which are the drive wheels, in a perfectly lateral direction.
More specifically, in a conventional fork lift 1a as illustrated in FIG. 15, a pair of front wheels (drive wheels) 3a are provided on the left- and right-hand sides on the front portion of the vehicle body 2a, a pair of rear wheels (steering wheels) 4a are provided on the left- and right-hand sides on the rear portion thereof, and a driver's area 5 is provided above the front portion of the vehicle body 2a. Vertically extendable masts 6 are provided on the front end section of the vehicle body 2a, rotatably in the front/rear direction by means of coupling axle 7a extending in the lateral direction of the vehicle, and a tilt cylinder 8 for performing front/rear rotation is provided between the vehicle body 2a and the masts 6.
The masts 6 comprise a pair of outer frames 9 arranged on the left- and right-hand sides on the fork lift 1a, and a pair of inner frames 10 that are arranged on the left- and right-hand sides and can be guided by the outer frames 9 to ascend or descend, a lift cylinder 11 being provided between the outer frames 9 and inner frames 10. Furthermore, lift bracket 12 that can be guided by the inner frames 10 to ascend or descend is also provided, and a pair of forks 13 are provided on the left- and right-hand sides on this lift bracket 12, via a pair of finger bars constituting upper and lower finger bars.
A seat 15 and a steering wheel 16, or the like, disposed to the front of this seat 15 are provided in the driver's area 5, and above these elements, a head guard 19 is provided via front pipes 17 and rear pipes 18 projecting from the main body 2a. A counter weight 20 is provided on the main body 2a, to the rear of the seat 15.
However, in a conventional fork lift 1a such as that described above, since the front wheels 3a are driven by a common travel drive train, it is not possible to steer these front wheels 3a in a perfectly lateral direction, and hence lateral travel cannot be achieved.
Moreover, since there are vehicle axles between the left- and right-hand front wheels 3a and between the left- and right-hand rear wheels 4a, and the battery must be installed in a position which avoids these axles, then these restrictions mean that installation and battery removal, in other words, maintenance tasks, cannot be performed readily. Moreover, there is also the possibility that the battery installation position will raise the center of gravity, leading to loss of stability.